I bought a six pack of rollers for my painting project. My better half suggested that I use the plastic bag to store the roller in between coats. It worked. I only used half of the rollers for a long hallway, ceilings, the dining room and the living room. Not too shabby.
The paint on the roller stayed wet for a week. This is a great idea if you are painting a large size room by section like I am. I also stored those squares you slide across so you don't have to tape the molding. I only bought one package of refills and only used 1. I don't recommend this for brushes because I found that paint will clump up the bristles. I just cleaned my brushes in between uses.